The XHTML WYSIWYG Editor For Desktop & Web Applications

h3

Definition

The elements h1 to h6 group the contents of a document into sections, and briefly describe the topic of each section. There are six levels of headings, h1 being the most important and h6 the least important.

Example

<h1>Product XYZ Documentation</h1>

<p>Text text text ...</p>

<h2>Getting Started</h2>

<p>Text text text ...</p>

Best practice

Document outline

Assistive technologies use headings to build a document outline (or table of contents). Therefore, headings should be organized in a tree-like structure that starts with the most important heading h1, followed by less important headings h2, h3, etc. The example below shows content organized using such a heading structure:

<h1>Welcome to ABC Inc.</h1>

<h2>What's New</h2>

<h3>Local News</h3>

<p>Text text text ...</p>

<h3>International News</h3>

<p>Text text text ...</p>

<h2>Events</h2>

<p>Text text text ...</p>

In this example, the document outline would look like this:

Welcome to ABC Inc.

What's New

Local News

International News

Events

Skipping heading levels is considered bad practice. For example, if the heading h1 is followed by the heading h3, the heading h2 will have been skipped.

Images in headings

Images can be used as headings, instead of text, provided the images have properly written alt text, such as that seen in the following example:

<h1>Welcome to ABC Inc.</h1>

<h2><img src="news.gif" alt="What's New" /></h2>

<p>Text text text ...</p>

<h2><img src="events.gif" alt="Events" /></h2>

<p>Text text text ...</p>

Anchors

Headings make great anchors for hyperlinks. For example:

<p><a href="#events">This month's public events</a></p>

...

...

...

<h2 id="events">January Events</h2>

Attributes

Common core attributes

class

(NameTokens) This attribute assigns a class name or set of class names to an element. Any number of elements may be assigned the same class name or set of class names. Multiple class names must be separated by white space characters. Class names are typically used to apply CSS formatting rules to an element.

id

(ID) This attribute assigns an ID to an element. This ID must be unique in a document. This ID can be used by client-side scripts (such as JavaScript) to select elements, apply CSS formatting rules, or to build relationships between elements.

title

(Text) This attribute offers advisory information. Some Web browsers will display this information as tooltips. Assistive technologies may make this information available to users as additional information about the element.

Common internationalization attributes

xml:lang

(NameToken) This attribute specifies the base language of an element's attribute values and text content.

dir

This attribute specifies the base direction of text. Possible values:

ltr: Left-to-right

rtl: Right-to-left

Common event attributes

onclick

(Script) A client-side script event that occurs when a pointing device button is clicked over an element.

ondblclick

(Script) A client-side script event that occurs when a pointing device button is double-clicked over an element.

onmousedown

(Script) A client-side script event that occurs when a pointing device button is pressed down over an element.

onmouseup

(Script) A client-side script event that occurs when a pointing device button is released over an element.

onmouseover

(Script) A client-side script event that occurs when a pointing device is moved onto an element.

onmousemove

(Script) A client-side script event that occurs when a pointing device is moved within an element.

onmouseout

(Script) A client-side script event that occurs when a pointing device is moved away from an element.

onkeypress

(Script) A client-side script event that occurs when a key is pressed down over an element then released.

onkeydown

(Script) A client-side script event that occurs when a key is pressed down over an element.

onkeyup

(Script) A client-side script event that occurs when a key is released over an element.

Common style attribute

style

(Text) This attribute specifies formatting style information for the current element. The content of this attribute is called inline CSS. The style attribute is deprecated (considered outdated), because it fuses together content and formatting.